expecting a baby. but the former kate middleton, the duchess of cambridge, is now not even 12 weeks along and her morning sickness is so severe she's now in the hospital. our senior medical correspondent, elizabeth cohen, is on the story for us. elizabeth, how often do women end up in the hospital with morning sickness during the first trimester? >> any woman can tell you, morning sickness is quite common, it happens to a lot of women. a relatively small percentage end up in the hospital. what's also interesting is morning sickness doesn't just happen in the morning. it can go on all day long. some women when they get to that 13, 14-week mark, it magically goes away. other women experience it all pregnancy long. >> what's the treatment? >> the treatment is, you put someone in the hospital if it's really severe because you need to get the medicines and nutrition and fluids iv. if the woman can't keep anything down, you give them anti-nausea medications iv. it has to be iv because she's throwing everything up. >> let's hope the best for kate, the former kate middleton, the duchess of

get through to be discussing kate middleton's health in any way. it doesn't defend what they did, and i'm not defending them, but i though i you have to put it into some kind of context. the ramifications of a silly prank could not have been more serious. >> a lot of people will have to take deep lessons, assuming the worst, that this woman was so distraught by what happened, she was blaming herself for embarrassing the royal family. my hope, and i hope it's yours as well, that some disk jockeys learn a lesson. you never know where it will wind up. >> the thing about pranks, they have been around for as long as we have been alive. i think you have to be very, very careful in you're in the world of broadcasting. they broadcast this life, and they didn't know what would happen. and at the very least, probably somebody who worked at the hospital would be compromised and made to look afool. and that, in itself, for a broadcaster, is unacceptable, if we pulled that stunt at cnn, i expect we would lose our jobs, and rightly. >> i covered it on my show, pointed out that the accents they